#1
What is the primary function of the heart in the human body?
Pumping blood
ExplanationThe heart pumps blood throughout the body, delivering oxygen and nutrients while removing waste products.
#2
What is the term for the maximum pressure exerted by the blood against the walls of the arteries during ventricular contraction?
Systolic pressure
ExplanationSystolic pressure is the highest pressure exerted by the blood on the arterial walls during ventricular contraction.
#3
During which phase of the cardiac cycle do the atrioventricular (AV) valves close to prevent the backflow of blood into the atria?
Ventricular systole
ExplanationAV valves close during ventricular systole to prevent blood from flowing back into the atria.
#4
What is the term for the volume of blood remaining in the ventricles at the end of ventricular diastole?
End-diastolic volume
ExplanationEnd-diastolic volume is the amount of blood in the ventricles at the end of diastole, just before systole begins.
#5
What is the term for the period of time during the cardiac cycle when the heart is at rest and chambers are filling with blood?
Diastole
ExplanationDiastole is the phase when the heart relaxes, chambers fill with blood, and coronary arteries supply the heart with oxygen.
#6
What is the term for the period during the cardiac cycle when the ventricles are contracting and pumping blood into the pulmonary and systemic circulation?
Systole
ExplanationSystole is the phase of the cardiac cycle when the heart contracts, pumping blood out into the pulmonary and systemic circulation.
#7
Which chamber of the heart is responsible for pumping oxygenated blood to the rest of the body?
Left ventricle
ExplanationThe left ventricle pumps oxygen-rich blood to the body's organs and tissues.
#8
What is the term for the relaxation phase of the cardiac cycle when the heart chambers fill with blood?
Diastole
ExplanationDiastole is the phase when the heart relaxes and fills with blood before the next contraction.
#9
What is the term for the volume of blood ejected by one ventricle of the heart during a single contraction?
Stroke volume
ExplanationStroke volume is the amount of blood pumped out by a ventricle with each heartbeat.
#10
Which of the following vessels carries oxygenated blood from the lungs to the left atrium of the heart?
Pulmonary vein
ExplanationThe pulmonary vein transports oxygenated blood from the lungs to the heart's left atrium.
#11
What is the primary role of the atrioventricular (AV) valves in the heart?
Facilitating blood flow from the atria to the ventricles
ExplanationAV valves prevent the backflow of blood from the ventricles to the atria, facilitating blood flow in one direction.
#12
Which of the following conditions is characterized by an irregular and often rapid heartbeat, disrupting the normal cardiac cycle?
Arrhythmia
ExplanationArrhythmia refers to abnormal heart rhythms, which can be irregular or too fast, disrupting normal heart function.
#13
Which blood vessels carry deoxygenated blood from the body back to the right atrium of the heart?
Veins
ExplanationVeins transport deoxygenated blood from the body's tissues back to the heart's right atrium.
#14
Which of the following represents the correct sequence of events during a complete cardiac cycle?
Atrial systole, ventricular systole, atrial diastole, ventricular diastole
ExplanationAtrial systole contracts the atria, followed by ventricular systole pumping blood, then both chambers relax in diastole.
#15
Which part of the heart's conduction system is responsible for initiating the heartbeat?
SA node (sinoatrial node)
ExplanationThe SA node generates electrical impulses, setting the heart rate and initiating heart contractions.
#16
During which phase of the cardiac cycle do the semilunar valves open to allow blood to be ejected from the ventricles?
Ventricular systole
ExplanationSemilunar valves open during ventricular systole, allowing blood to leave the heart and enter the arteries.
#17
Which of the following hormones is produced by the heart and plays a role in regulating blood pressure?
Atrial natriuretic peptide (ANP)
ExplanationANP helps regulate blood pressure and fluid balance by promoting sodium and water excretion by the kidneys.
#18
Which component of the heart's electrical conduction system is responsible for delaying the impulse to allow for atrial contraction before ventricular contraction?
AV node (atrioventricular node)
ExplanationThe AV node delays electrical impulses, allowing the atria to contract before the ventricles.
#19
Which of the following factors can influence heart rate regulation?
Temperature
ExplanationTemperature affects heart rate; increased temperature can lead to increased heart rate, while decreased temperature can lower it.
#20
In which phase of the cardiac cycle does the aortic valve open to allow blood to be ejected into the systemic circulation?
Ventricular systole
ExplanationThe aortic valve opens during ventricular systole, allowing blood to flow from the left ventricle into the aorta and systemic circulation.